The Sum 1/(1+(5/n))*5/n+1/(1+10/n))*5/n+1/(1+15/n)*5/n+.....1/(1+5n/n))*5/n

is a riemann sum for a definite integral

⌠b
⌡1f(x) dx

using a partition of the interval [1,b] into n subintervals of equal length,
Then the upper limit of integration must be: b =
and the integrand must be the function f(x) =

You realize that it's almost impossible to understand the expression you wrote, don't you?
Try again, add more parentheses and spaces if and where needed (but not more than needed!), or better: write with LaTex.